Pipe clamp



Nov. 27, 1928. 1,693,478

' M. B. DAVIS PIPE CLAMP Filed Aug. 21, 1925 3 Sheets-Sheet 2 iNVENTOR ATTRNEY M. B. DAVIS PIPE CLAMP Filed Aug. 21, 1925 3 Sheets-Sheet i INVENTOR Y l /W/m MEV,l

Patented Nov. 227, 1928.

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Miatvni B. Davis; oriKNsAjscIr-Y,

Missionnijasfsieiioirro enonen" KRE'LL, or

PIPE CLAMP.

Application ied Ang-ust 21', 1925. serial No; 51,5e3'.'

o which will hereinafter be referred to as pipel with the understanding that such term is sufiiciently comprehensive to include any forni of obj ect with which the invention may be employedg-the principal object of the invention being to eect application of the clamp to the body ofa pipe as distinguished from the connections or couplings asin the common practice,

In pulling'and setting pipe it is'desirable to l grip Vthe pipe as. near the end aspossible and in some forms of clamps heretofore employed, the load is applied to the coupling collar, with the not infrequent result that the collar collapses under the strain. Vf ith my invention avoid application of the load to the collar, but l do, however, employ the collars as means for veffecting application Aof 'the clamp to the body of the pipe below'thecollar.

In; accomplishing this and other objects rof tliein'vention, Ihave provided improved de'- tails of structurehereinafter described and illustratedin the accompanying drawings, wherein F ig. 1 is a perspective View of a clamp embodying my improvement, showing the clamp in open position ready 'for application to a section' of pipe. l

Fig. 2 is a plan view of the clamp asapplied to the pipe, and after` the slips are set.

Fig.v 3 is aivertical, sectional view `of the cla-mp, shoxvingtlie Vsetting' members in feeling' relation to the'pipe.A

Fig. is a similar view, showing the jaws Vset in gripping Contact with the pipe.

Fig; 5 is a vperspective view of the clamp frame, the slips and' slip-setting mechanism being removed for better illustrz'rtion.` y

F ig. 6 is a detail perspective view of a pair of slips.` j Figq `isa perspective vi'ewof oneof the slip-setting levers,` and Fig. 8 Aa lo'ngitudina'l,V sectionaly view through'theioperatingihandle. `1 `V Referringlmore infdetail'to the drawings by numeralsof reference,l u

1 designates a slip "carrying-'frame comprising riglitaiid left halvesf2 and 3, each seniic'ircularin crossseotion, and; hingedly connected by 'af pin 4L Isothat they may open andicloseabouta pipea-nd belat'ched'by a CAB latching mechanism 5, hereinafter described. The members 2 and 3 'are duplicates exceptfor the latch elements. Each half is provided with hinge lugs 6 spaced to meshwith like lugs on the niatingjhalf, the lugs being provided with openings to receive the pin 4f. The latch mechanism comprises ears 7 and 8 on the left half adapted to mesh with pairs of ears 9 9 and 10-10 on the right half.

' The ears are provided with openings `11 for receiving the ends12 and 13 ofa latching bar 14 having a handle 15 which may be employed by the operator for manipulating the right halfof the clamp, afndrfor his convenience I provide Vthe left half with a handlebar 16 for operating that half. To prevent liftingV of the latchout of the top ear 9, I provide the enld 12 oft-he latch witha 'slot 17 which engages aV pin 18 ini the ear to limit the movement of the latch bar and retain it in functionai position (Fig. 8).

Extending upwardly and outwardly from the top of each of the frame members, and preferably integral therewith, are paired ears 19-19 having' openings 20 within which is rotatably mounted the shaft 21 of 'a slipopera-ting and supporting lever 22. The shaft 21 is here shown as a bolt provided with a nut 23 'for retaining the bolt in place and itself keyed bya Cotter pin 24.V

Each slip-operating lever comprises a sleeve or huh 25 having an outwardly extending arm 26 provided `with a hooked end 27 to form a seat 28 for receiving the cross bar 29 of a hanger vlink 30 by which the clamp suspended from the tackle mechanism (not shown). Also extending' from the hub 25, opposite the arm 26 and' projecting toward the center ofthe clamp is Ka pair of slip-carrying arms 31 and 32, having inturnedl lingers 31', 32". i

l. provide a pair of slips 33, 34 for each `half of the clamp,`each slipbeingpreferably quarter round in cross section and `elongated with its outer face, 35, tapered to conform to the tapered bore 36 of its frame member, to aiford a radial wedgingaction when t-he slips are yforced down withintheframe members 2an'd 3.V l Each slip is provided' at itsupper end with an ear`37 Ahaving an aperture 3S to receive the finger 31 or 32 o-f a'eompleiiieiitary rcarryingl arm 31er 32,'and' is. retained thereon by a 'Cotter pin 39 or the like which extends through an opening 39" in the carrying-finger. The alfierture 3S in the ear of the slip is somewhat larger than the finger, and preferably oval shaped to permit longitudinal play of the slips without binding of the connection, when the arms move in a circular path and the slips somewhat vertically during setting travel ofthe slips.

The slips are provided on their inner surfaces with 'teeth i0 to insure a firm grip of the pipe, and are so assembled within the frame members lthat each pair forms a vertically divided, substantially semi-circular gripping` jaw on each half of the frame so that when the clamp is closed about the pipe fl-l, the slips combine to grip the pipe as illustrated in Figs. Q and si..

It `is desirable that the clamp taire hold only near the end of a pipe section, and to insure this positioning and 'also to avoid necessity for manual closing of the slips, I provide for preliminary application o-f the clamp to the pipe at any point throughout its length, and automatic closing of the jaws only at the desired location adjacent the end of the pipe. In this way it is possible to apply the clamp atany convenient point in the length of the pipe, then lift the clamp idly over the pipe until it reaches the clamping position, where automatic action is effected to close the slips on the pipe, so that continued lifting of the clamp carries the pipe along with the clamp. To accomplish this it is necessary to have the slips normally spread sufficiently to permit idle movement over the pipe. rIhis is accomplished by springs 42, one for each slip-actuating lever. The springs are preferably coiled in tension, one end of each spring being fastened to a lug i-3 extending outwardly from the bottom edge of the frame, and the other end hooked in an opening lll in the end of its complement-ary slip lever arm 27. The combined strength of the two springs is: somewhat greater than the weight of thefclamp, consequently, the arms 2r of the slip levers are normally roel-ted downwardlv and the slipsupporting arms inLnva-rd under tension of the springs, as illust-rated in Fig. I3, thus normally holding the slips away from the pipe to provide clearance between the slips and pipe and to permit the cla-mp to move idly over the pipe. To overcome this spring tension and set the jaws or slips, I provide each slip-actuating lever with an inwaully eX- tendin'g feeler arm 4.5, comprising a flat spring secured to the. top of each lever by screws 4G and provided with a head at? having anA inwardly opening, circ-uhu' recess -iS oi' slightly greater diameter than the "pipe but of smaller diameter than the couplingl collar Li9 on the end of the pipe, so that when the feelers reach the collar, theyL are stopped thereby and hold against further movement along` the pipe. Continued upward moveinentof theA clamp frame causes the slip levers to rock against the tension of the springs Ll2 so that movement of the slips is reversed and the tapered bore of the frame moving upwardly over the oppositely tapered walls of the downwardlyA moving slips cam the slips inwardly to grip the pipe, so that further upward movement of the frame causes the Vpipe to move alo-ng with the clamp.

To protect the springs 42 from being accidentally displaced or broken, I provide each member 2 and 3 with wings 50 and 5l between which the springs are housed,

While l have included description of operation of the clamp along with the description of its structure, the operation may be briefly stated as follows:

Assuming the clamp to be constructed and assembled as described, and to be employed for setting pipe, and assuniinga stack of pipe sec-tions in the derricl, with their coupling collars at the top, the operator on the tubing board tilts a section of pipeagainst the linger board,lswings the clamp over it and fastens the latch, the clamp usually being applied about 8 or l0 feet below the npper end of the pipe. rlhe tackle thenflifts the clamp, which slides over the pipe until the feeler heads engage the coupling collar, when movement of the clamp along` the pipe is stopped and the slips moved against the pipe. As movement of the tackle is continuous, setting of the slips is practically instantaneous and lift of the clamp is uninterrupted, the only difference being that prior to the setting of the slips the clamp moves idly over the pipe whileV afterwards the pipe is carried with the clamp. rlhe slipsha-ving gripped the pipe, the latter is elevated, carried to position, and lowered to connect with pipe already in the well, after which the clamp is unlatched by an operator at the. well platform and the clamp sent bach for a new section of pipe, the springs 4Q automatically rockingthe stop levers to spread the. slips to release the held pipe and prepare the clamp for a new section when the clamp is relieved from weight of the pipe.

When ipe is to be pulled, the operation described is reversed, the operation of the clamp itself, however, being` the same.

What I claim and. desire to secure by Letters-Patent is l. A clamp comprising a frame includingl hingedly connected members adapted to close about an object to be clamped, slips loose y mounted in the frame and means on the frame and engageable with an object to be clamped to interrupt travel of the slips with the frame, the frame being operable on the'slipsto effect radial closing movement thereof upon continued movement ofthe frame. i

2. A clamp comprising a frame including hingedly connected members adapted to close about an object to loe clamped, slips carried Sii by and movable relative to the frame, and means on the frame and engageable with an obstruction on the object to be clamped to interrupt travel of the slips, the frame and slips having complementary cam surfaces Vwhereby the held slips are moved radially lto gripping position upon continued travel of pleinentary cam surfaces for effecting radial closing movement of the slips upon continued longitudinal travel of the frame. 4. A clamp comprising a frame including hingedly connected members adapted to close about an object to be clamped and having a downwardly tapering bore, tapered slipsv loseely suspended in said bore, means normally, yieldingly retaining the slips in spaced relation, and means 0n the frame and engageable with an obstruction ,on the object to be clamped in the path of the clampto initiate closing movement of the slips, the frame exeiting closing pressure on the slips upon continued travel of the frame.

5. A clamp comprising a frame, levers axially mounted in the frame, slips mounted on said levers for `i'adial and longitudinal movement relative to the frame, means noi14 inally, yieldingly retaining the levers in slip retracting position, and feeler arms connected with the levers and engageable with an 0bstruction in the path of the clamp, to shift the levers and initiate closing movement of the slips against the tension of said yielding means, the frame being engageable with the slips to exert gripping pressure thereof upon continued travel ofV the frame. Y,

6. In a clamp, a frame comprising a tapered bore, levers axially mounted on tlie frame and comprising axle members, tapered slips axially and slidably moveable on said members, means normally, yieldingly retaining the levers in retracted position, and

Y feeler arms on the levers engageable with an obstruction in the path of the clamp to rock the levers and initiate closing movement of the slips, the tapered surfaces of the frame and slips co-operating tojeifect further closing travel of the slips upon continued longitudinal travel of the fraine.

7. A clamp comprising frame members,

levers pivotally mounted on the frame members, slips mounted on the inner ends of tlie levers, hanger links engageable with the ends of the levers opposite the slips to support the clamp, and means on the levers engageable with an obstruction, to rock the levers and shift the slips to gripping position.

8. A clamp comprising frame members having complementary tapered bore portions, levers'pivotally mounted in the frame meinbers, tapered slips loosely suspended from the levers into the bore portions of the frame members, hanger links suspending the frame from said levers, springs connecting the levers and frame members, to normally retain the levers in retracted position against the weight of the frame, and feeler arms on the levers engageable with an obstruction to shift the levers against the tension of said springs and effect initial closing movement of the slips, the tapered surfaces of the frame and slips co-operating to effect further closing movement of the slips upon continued longitudinal movement of the frame.

9. A clamp of the character described comprising a frame having a tapered bore, slips having tapered walls engageable with the bore to clamp the slips against an object to be clamped when the frame is lifted with the slips in engagement with the object, means automatically opening the slips when relieved of weight of the object, and means, associated with the automatic opening means, suspending the frame and tending to close the slips.

l0. A clamp of the character described comprising a frame having a tapered bore, slips having tapered walls engageable with said bore to close the slips against an object to be clamped, levers on said frame suspend ing the slips in the bore, means engaging the levers for suspending the frame, means yieldingly resisting tendency of said suspending means to close the slips against thepbj ect, and means for initiating closing movement of the slips.

ll. A clamp of the character described comprising a frame movable along an object to be clamped and having a tapered bore, slips having tapered walls for engaging said bore to close the slips, means associated with the slips for suspending the frame and closing the slips, and means normally resisting closing of the slips and adapted for automatically opening the slips when the slips are relieved of excessive closing thrust.

In testimony whereof I aiiix my signature.

MARVIN E. DAVIS llO 

